Ministry of Environment
Sensitive
Ecosystems Inventories
Coastal Bluff Ecosystems of Eastern Vancouver Island and the Gulf Islands
Coastal Bluff ecosystems are found on the coast from the water’s edge to lands just above the high tide mark. Many distinct plant communities have developed in response to this relatively harsh environment of crashing waves, currents, tides, winds, heat, storms and salt spray.
Coastal Bluff ecosystems have been divided into two distinct categories: vegetated rocky islets and shorelines (CB); and vegetated coastal cliffs and bluffs (CB:cl). These two categories encompass several different landforms that provide specialized wildlife habitats, and support distinct plant communities.
How are Coastal Bluffs distinguished from other SEI ecosystems?
- Lack of Soils – CB ecosystems
usually have shallow soils. Outwash deposits left in rock crevices
and depressions sheltered from prevailing winds give rise to dry,
nutrient poor sand and sandy-loam soils. Due to the harsh environment
and steep slopes, accumulation of organic matter into distinct horizons
may take years and is usually limited to bedrock fissures on cliffs
and bluffs.
- Sparsely Vegetated – CB ecosystems lack continuous vegetation cover due to nutrient poor soils and exposed bedrock. However, CB ecosystems may be interspersed with other SEI ecosystems such as Terrestrial Herbaceous (HT), Woodland (WD), Older Forest (OF), and Sparsely Vegetated (SV).
Why are Coastal Bluff ecosystems considered ecologically important?
- CB ecosystems have high biodiversity
– Coastal Bluff ecosystems support a large number of plant and
animal species that have adapted specifically to this harsh environment.
- CB ecosystems provide specialized habitats for a number of rare and specialized species – Coastal Bluff ecosystems are rare and contain highly specialized habitats for many species unique to these areas. Some of these species, such as Macoun's meadowfoam and water-plantain buttercup, are rare and only known to occur in these ecosystems. In addition, open ledges and horizontal fissures on cliffs and bluffs are known to provide the best nesting sites for red and blue-listed birds such as the turkey vulture and pelagic cormorant.
What are some conservation concerns of Coastal Bluff terrestrial ecosystems?
Coastal Bluff ecosystems are characterized by soils which accumulate very slowly and only in isolated micro-sites. This factor, combined with the characteristically thin organic layer that protects the soil from erosion and disturbance, makes these areas extremely susceptible to any type of use and development. The largest direct impact for Coastal Bluffs is by humans seeking the highly desirable beach front property for tourism, commercial, and residential purposes.
Top